System and method for differential etching

ABSTRACT

A plasma sputtering apparatus according to one embodiment includes a chamber and a reservoir in fluidic communication with the chamber. The reservoir stores a vapor source therein, and is configured to release vapor at a predetermined rate. The vapor released by the reservoir is effective to diminish an etch rate of a first magnetic material, the vapor having a smaller effect on an etch rate of a second magnetic material that is different than the first magnetic material. The apparatus also includes a mount for a substrate and a plasma source.

BACKGROUND

The present invention relates to selectively etching portions of asubstrate, and more particularly, this invention relates to a system andmethod for controlling the differential etch rate difference between oneor more materials of a substrate.

Techniques for etching substrates, such as microelectronic devices,magnetic heads, etc., are known in the art. Conventional etchingprocesses include, for example, inert gas plasma sputtering, ion millingor reactive ion etching, etc. In these processes, etching occurs as aresult of physical impingement of ions on the surface of the substrateto be etched, or as a result of interaction between the impingement ionsand the etched surface, or both. However, only small differential etchrates have been achieved in these processes, by varying the impingementangle.

BRIEF SUMMARY

A plasma sputtering apparatus according to one embodiment includes achamber and a reservoir in fluidic communication with the chamber. Thereservoir stores a vapor source therein, and is configured to releasevapor at a predetermined rate. The vapor released by the reservoir iseffective to diminish an etch rate of a first magnetic material, thevapor having a smaller effect on an etch rate of a second magneticmaterial that is different than the first magnetic material. Theapparatus also includes a mount for a substrate and a plasma source.

A plasma sputtering apparatus according to another embodiment includes achamber and a reservoir in fluidic communication with the chamber. Thereservoir is configured to release a vapor at an established rate. Thereservoir comprises a porous material selected from the group consistingof: a metal oxide, silicon nitride, silicon carbide, and combinationsthereof. The apparatus also includes a mount for a substrate and aplasma source.

Other aspects and embodiments of the present invention will becomeapparent from the following detailed description, which, when taken inconjunction with the drawings, illustrate by way of example theprinciples of the invention.

BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWINGS

FIG. 1 is a flow diagram of a method according to one embodiment.

FIG. 2 illustrates a side view of a flat-lapped, bi-directional,two-module magnetic tape head according to one embodiment

FIG. 2A is a detailed view of a partial tape bearing surface of a pairof modules.

FIG. 2B is a partial cross-sectional view of a module according to oneembodiment.

FIG. 3 is a flow diagram of a method according to one embodiment.

FIG. 4 illustrates a schematic diagram of a plasma sputtering apparatusaccording to one embodiment.

FIGS. 5A-5C depict results of etching processes according to oneembodiment.

FIGS. 6A-6C depict results of etching processes according to oneembodiment.

DETAILED DESCRIPTION

The following description is made for the purpose of illustrating thegeneral principles of the present invention and is not meant to limitthe inventive concepts claimed herein. Further, particular featuresdescribed herein can be used in combination with other describedfeatures in each of the various possible combinations and permutations.

Unless otherwise specifically defined herein, all terms are to be giventheir broadest possible interpretation including meanings implied fromthe specification as well as meanings understood by those skilled in theart and/or as defined in dictionaries, treatises, etc.

It must also be noted that, as used in the specification and theappended claims, the singular forms “a,” “an” and “the” include pluralreferents unless otherwise specified.

The following description discloses several preferred embodiments of thepresent invention, as well as operation and/or component parts thereof.

In one general embodiment, a method includes placing a substrate in achamber; and plasma sputtering the substrate in a presence of a non-zeropressure of a vapor, wherein the vapor at the non-zero pressure iseffective to diminish an etch rate of a first material of the substrate.

In another general embodiment, a method includes placing a substrate ina chamber, wherein the substrate includes a magnetic head; and plasmasputtering the substrate in a presence of a non-zero pressure of avapor, wherein the vapor at the non-zero pressure is effective todiminish an etch rate of at least one write pole of the magnetic head,wherein the presence of the vapor has a smaller effect on an etch rateof at least one reader shield of the magnetic head.

In one general embodiment, a plasma sputtering apparatus includes achamber; a reservoir in the chamber for releasing a vapor at anestablished rate; a mount for a substrate; and a plasma source.

In conventional high vacuum etching processes, e.g. inert gas plasmasputtering, ion milling, reactive ion etching, etc., etching typicallyoccurs as a result of physical impingement of ions on the surface to beetched, as a result of interaction between the impingement ions and theetched surface, etc. While the impingement angle is often varied inthese conventional etching processes to etch certain classes ofmaterials at different rates, only small differential rates have beenachieved.

Embodiments of the present invention overcome the aforementioneddrawback by providing a system and method for altering susceptibility toetching via selective in-situ interactions between a selected materialand etching inhibiting agent to achieve large differential etchingrates. For example, a surface chemistry reaction may be utilized in someembodiments to diminish the etch rates for specific materials.Preferably, the overall etch rate may be low to allow a surfaceinteraction to be more effective for some materials than other, in someembodiments.

In preferred embodiments, the system and method may be used forprofiling magnetic recording head surfaces to minimize surface shortingdue to permalloy (nickel-iron alloy) smearing. For instance, etching maybe performed to recess the ductile permalloy below the sensor layersaccording to various embodiments.

Further, the inventors were surprised to discover that when the etchingis performed in the presence of water vapor as described in theembodiments herein, unexpected and surprising results manifest,including a large observable shift in etch rates for certain materialsand not others. Unlike previously known etching methods and systemswhere water vapor is intentionally thoroughly pumped out of the vacuumsystem, preferred embodiments of the present invention etch or profile asubstrate in the presence of a selected and controlled pressure of watervapor.

While the precise mechanism that enables control of the relative etchingrates was previously unrecognized, and could not have been predicted,without wishing to be bound by any theory, it is presently hypothesizedthat the water vapor has an affinity to iron, where the water and/oroxygen species may bind to or otherwise react with the alloy inproportion to the iron content. It is believed that the higher the ironcontent, the more the water vapor tends to aggregate at the surface ofthe alloy, thereby providing a barrier at the molecular level to theincoming ions and consequently retarding the etch rate.

The approaches presented herein are applicable to a wide variety ofprocesses for fabricating any type of device, including magnetic heads,sensors, circuits, chips, processors, etc. To place various embodimentsin a context, and done solely by way of example and not limitation,several embodiments are described in terms of processing a magnetichead. Again, this is done by way of example to assist the reader, andthose skilled in the art of thin film and/or semiconductor processingwill appreciate the plethora of possible applications of the teachingherein.

In one illustrative example, at least one write pole comprising a higheriron-containing nickel-iron alloy (e.g., 45 at % Ni/55 at % Fe) may etchat rate that is substantially slower, e.g. up to about 9 times slower,than at least one permalloy (e.g., 80/20 NiFe) reader shield duringplasma sputter etching, also referred to herein as plasma sputtering.This unexpected and surprising result—the large differential etching inthe presence of the water vapor—enables achieving essentially zerorecession write poles in addition to achieving the original intendedpurpose of protecting the sensor from surface smearing by selectivelyrecessing portions of the sensor.

Additionally, in preferred embodiments, the system and method mayprovide a means for controlling water vapor pressure in a system capableof producing a high vacuum, such as is required for sputter depositionof thin film layers. Particularly, exemplary embodiments may provide aporous aluminum oxide structure to serve as a reservoir for water, whichmay subsequently release water at an established rate during etchingand/or the pumping down of the vacuum system. In one embodiment, thestructure is proximate to or serves as a pallet for holding thesubstrate or substrates.

The rate at various pressures may be established via known techniquesusing routine experimentation, as would be apparent to one skilled inthe art upon reading the present disclosure. Furthermore, the claimedsystem and method may support etching with, or in the absence of,hydrogen gas.

FIG. 1 shows a method 100 in accordance with one embodiment. As anoption, the present method 100 may be implemented in conjunction withfeatures from any other embodiments listed herein, such as those shownin the other FIGS. Of course, however, this method 100 and otherspresented herein may be used in various applications and/orpermutations, which may or may not be related to the illustrativeembodiments listed herein. Further, the method 100 presented herein maybe carried out in any desired environment. Moreover, more or lessoperations than those shown in FIG. 1 may be included in method 100,according to various embodiments.

As shown in FIG. 1 according to one approach, the method 100 includesplacing a substrate in a chamber. See operation 102. The method 100 alsoincludes plasma sputtering the substrate in a presence of a non-zeropressure of a vapor, where the vapor at the non-zero pressure iseffective to diminish an etch rate of a first material of the substrate.See operation 104. As used herein, the vapor may include, but is notlimited to, water vapor.

According to one embodiment, the plasma sputtering may be performed in avacuum.

In another embodiment, the vapor may be released during a pump-downprocedure for creating the vacuum.

Preferably, the vapor may originate from a reservoir in the chamber. Thereservoir may include a porous structure, in accordance with oneapproach. The porous structure may comprise porous materials including,but not limited to, ceramics; metal oxides such as aluminum oxide,titanium oxide; zirconium dioxide (zirconia); silicon nitride, siliconcarbide; etc. or other porous materials suitable to contain and releasevapor (e.g. water vapor) as would be understood by one having skill inthe art upon reading the present disclosure. In some embodiments, theporous structure is an oxygenated material that may release oxygenduring the sputtering process. Oxygen may assist in the effect of thewater. The reservoir may be a flame coated substrate employing any ofthe foregoing materials. The reservoir may be positioned anywhere in thechamber, such as along one side of the chamber, over or under thesubstrate, in or along the mount, etc., or in some embodimentsincorporated with the pallet used to hold the substrate, therebyproviding a local source of water vapor.

In another approach, the reservoir could be external to the chamber, andthe water vapor injected into the chamber in a controlled manner.

The reservoir, according to another approach, may release the vapor atknown rates at particular vacuum pressures.

The pressure of the water vapor in the chamber generally refers to thepressure of the water vapor which is being released by the reservoir.Several exemplary pressures of the vapor are presented herein, and aregenerally suitable for etching where the temperature of the substrate isto be kept below 70° C., However, it should be kept in mind that thepressure may be adjusted to values above and/or below the disclosedvalues depending on the plasma energy and/or the accelerating voltageused in a given process. One skilled in the art, upon being apprised ofthe teachings herein, could determine workable ranges without undueexperimentation.

In one illustrative approach, the non-zero pressure of the water vapormay be achieved at pressures greater than 10⁻⁷ Torr. In a preferredembodiment, the pressure of the vapor may be between 10⁻⁵ and 10⁻⁷ Torr,depending on the plasma energy. This range has been found to provide thesurprising and unexpected result of differential etching rates of layershaving different iron composition. Those skilled in the art, now beingapprised of the present disclosure, would be able to extend theteachings presented herein to other materials systems to determine watervapor pressures that afford similar differential etching rates for suchmaterials systems without undue experimentation.

In a further embodiment, a desired amount of water vapor in the chambermay be based on an impingement ratio. As used herein, the impingementratio may be defined as the number of vapor molecules striking thesubstrate per unit of time divided by the number of plasma ions strikingthe substrate per unit time, where the numbers of molecules and atomscan be estimated or calculated using any known method.

Additionally, in one embodiment, substantially no hydrogen gas may bepresent in the chamber during the plasma sputtering. This statementencompasses presence of trace amounts (e.g., below 1 at %) of hydrogendue, for instance, to a trace presence of hydrogen in a feed gas.Further, the present of trace amounts of hydrogen in the chamber may bedue to the inherent inability to remove every atom of all substancesfrom the chamber during the pump down procedure of the chamber, etc.

According to various approaches, hydrogen gas may or may not be(purposefully) added to the chamber during the plasma sputtering. Theplasma may include an ionized noble gas, such as argon, and so asputtering target is not required.

The method 100 may further comprise forming portions of the substrate inthe chamber prior to and/or after the plasma sputtering, in oneembodiment. For example, a coating may be added to the device after theplasma sputtering.

In another embodiment, the substrate may include a first material.According to one approach, the first material of the substrate may be analloy comprising a first concentration of iron. In yet anotherembodiment, the substrate may also include a second material, whereinthe second material of the substrate may be an alloy comprising a secondconcentration of iron different than the first concentration of iron ofthe first material. For example, the first material may comprise greaterthan 30 at % iron and the second material may comprise less than 30 at %iron, in one approach. In a preferred approach, the first material maycomprise approximately 45 at % nickel and 55 at % iron, and the secondmaterial may comprise approximately 80 at % nickel and 20 at % iron. Inanother exemplary approach, the first material may comprise Al—Fe—Si(Sendust), where the iron is approximately 81 at %. Sendust is notductile and is wear resistant; thus the first material comprisingSendust may provide additional durability, in some embodiments. Forinstance, said additional durability may protect against tape wear inmagnetic heads, especially for those having little or no Sendustrecession.

In a further embodiment, the second material may be exposed to theplasma sputtering, where the presence of the vapor may have a reduced,and preferably negligible, effect on an etch rate of the secondmaterial. As used herein, negligible signifies that the etch rate iswithin 20% of what the etch rate would be in the absence of the vapor.

However, in one approach, the etch rate of the first material may bediminished by at least 2 times in the presence of the vapor. Accordingto another approach, the etch rate of the first material may bediminished by more than 4 times, e.g., at least 5 times, at least 6times, at least 7 times, at least 8 times, at least 9 times, etc. Forinstance, in a preferred approach where the first material may comprise45 at % nickel and 55 at % iron, and the second material may comprise 80at % nickel and 20 at % iron, the first material may be etched at a rateup to about 9 times slower than that of the second material. Asdescribed above, the diminishment of the etch rate of the first materialin the presence of vapor is an unexpected and surprising result.

In addition, the substrate of method 100 may include a magnetic head, asshown in FIG. 2 according to one embodiment. In one approach, the atleast one shield of the magnetic head may be formed of the secondmaterial, wherein at least one write pole of the magnetic head may beformed of the first material.

By way of example, FIG. 2 illustrates a side view of a flat-lapped,bi-directional, two-module magnetic tape head 200, which may beimplemented in the context of the present invention. As shown, the headincludes a pair of bases 202, each equipped with a module 204, and fixedat a small angle α with respect to each other. The bases may be“U-beams” that are adhesively coupled together. Each module 204 includesa substrate 204A and a closure 204B with a thin film portion, commonlyreferred to as a “gap” in which the readers and/or writers 206 areformed. In use, a tape 208 is moved over the modules 204 along a media(tape) bearing surface 209 in the manner shown for reading and writingdata on the tape 208 using the readers and writers. The wrap angle θ ofthe tape 208 at edges going onto and exiting the flat media supportsurfaces 209 are usually between about 0.1 degree and about 5 degrees.

The substrates 204A are typically constructed of a wear resistantmaterial, such as a ceramic. The closures 204B made of the same orsimilar ceramic as the substrates 204A.

The readers and writers may be arranged in a piggyback or mergedconfiguration. An illustrative piggybacked configuration comprises a(magnetically inductive) writer transducer on top of (or below) a(magnetically shielded) reader transducer (e.g., a magnetoresistivereader, etc.), wherein the poles of the writer and the shields of thereader are generally separated. An illustrative merged configurationcomprises one reader shield in the same physical layer as one writerpole (hence, “merged”). The readers and writers may also be arranged inan interleaved configuration. Alternatively, each array of channels maybe readers or writers only. Any of these arrays may contain one or moreservo track readers for reading servo data on the medium.

FIG. 2A shows a partial tape bearing surface view of complimentarymodules of a magnetic tape head 200 according to one embodiment. In thisembodiment, each module has a plurality of read/write (R/W) pairs in apiggyback configuration formed on a common substrate 204A and anoptional electrically insulative layer 236. The writers, exemplified bythe write head 214 and the readers, exemplified by the read head 216,are aligned parallel to a direction of travel of a tape mediumthereacross to form an R/W pair, exemplified by the R/W pair 222.

Several R/W pairs 222 may be present, such as 8, 16, 32 pairs, etc. TheR/W pairs 222 as shown are linearly aligned in a direction generallyperpendicular to a direction of tape travel thereacross. However, thepairs may also be aligned diagonally, etc. Servo readers 212 arepositioned on the outside of the array of R/W pairs, the function ofwhich is well known.

Generally, the magnetic tape medium moves in either a forward or reversedirection as indicated by arrow 220. The magnetic tape medium and headassembly 200 operate in a transducing relationship in the mannerwell-known in the art. The piggybacked MR head assembly 200 includes twothin-film modules 224 and 226 of generally identical construction.

Modules 224 and 226 are joined together with a space present betweenclosures 204B thereof (partially shown) to form a single physical unitto provide read-while-write capability by activating the writer of theleading module and reader of the trailing module aligned with the writerof the leading module parallel to the direction of tape travel relativethereto. When a module 224, 226 of a piggyback head 200 is constructed,layers are formed in a gap 218 created above an electrically conductivesubstrate 204A (partially shown), e.g., of AlTiC, in generally thefollowing order for the R/W pairs 222: an insulating layer 236, a firstshield 232 typically of an iron alloy such as NiFe (permalloy), CZT orAl—Fe—Si (Sendust), a sensor 234 for sensing a data track on a magneticmedium, a second shield 238 typically of a nickel-iron alloy (e.g.,˜80/20 at % permalloy), first and second writer pole tips 228, 230, anda coil (not shown). The sensor may be of any known type, including thosebased on MR such as GMR, AMR, tunnelling magnetoresistance (TMR), etc.

The first and second writer poles 228, 230 may be fabricated from highmagnetic moment materials such as ˜45/55 at % NiFe. Note that thesematerials are provided by way of example only, and other materials maybe used. Additional layers such as insulation between the shields and/orpole tips and an insulation layer surrounding the sensor may be present.Illustrative materials for the insulation include alumina and otheroxides, insulative polymers, etc.

FIG. 2B illustrates exemplary result of a plasma sputtering process on amagnetic head such as that shown in FIG. 2A having permalloy shields and45/55 NiFe write poles. As shown in FIG. 2B, the one or more writetransducers 214 may include first and second write poles, 228 and 230,respectively, having media facing sides that may be recessed a depth d₁from a plane 240 extending along the media facing side 209 of the module204, according to one embodiment. In various approaches, it may befavorable to minimize the spacing loss between the one or more writetransducers 214 and the media, e.g. tape or disc, in order to maximizethe accuracy of the one or more write transducers 214. Accordingly, itmay be preferable, in certain approaches, to minimize the recession ofthe one or more write transducers 214 from the plane 240.

With continued reference to FIG. 2B, the media facing side of the firstshield 232 and the second shield 238 of the one or more read transducers216 may be recessed a depth d₂ from the plane 240, in accordance withone embodiment. In some approaches, the recession of the one or moreshields (e.g. 232 and 238) of the one or more read transducers 216 maybe favorable to protect the read sensor 234 from wear.

Referring now to FIG. 3, a method 300 is shown in accordance with oneembodiment. As an option, the present method 300 may be implemented inconjunction with features from any other embodiments listed herein, suchas those shown in the other FIGS. Of course, however, this method 300and others presented herein may be used in various applications and/orpermutations, which may or may not be related to the illustrativeembodiments listed herein. Further, the method 300 presented herein maybe carried out in any desired environment. Moreover, more or lessoperations than those shown in FIG. 3 may be included in method 300,according to various embodiments.

As shown in FIG. 3 according to one approach, the method 100 includesplacing a substrate in a chamber, wherein the substrate includes amagnetic head. See operation 302. Additionally, the method 300 includesplasma sputtering the substrate in a presence of a non-zero pressure ofa vapor, where the vapor at the non-zero pressure is effective todiminish an etch rate of at least one write pole of the magnetic head,wherein the presence of the vapor has a reduced, and preferablynegligible, effect on an etch rate of at least one reader shield of themagnetic head. See operation 304. Of particular note is the unexpectedand surprising diminishment of the etch rate of the at least one writepole of the magnetic head in the presence of the non-zero pressure ofthe vapor.

According to one embodiment, the plasma sputtering may be performed in avacuum.

In some approaches, hydrogen gas may be present in the chamber duringplasma sputtering.

In another embodiment, substantially no hydrogen gas may be present inthe chamber during the plasma sputtering. This statement encompassespresence of trace amounts (e.g., below 1 at %) of hydrogen due, forinstance, to a trace presence of hydrogen in a feed gas. Further, thepresent of trace amounts of hydrogen in the chamber may be due to theinherent inability to remove every atom of all substances from thechamber during the pump down procedure of the chamber, etc.

In yet another embodiment, the vapor, e.g. water vapor, may originatefrom a reservoir in the chamber. The reservoir may include a porousstructure, in accordance with one approach. The porous structure maycomprise porous materials including, but not limited to, ceramics; metaloxides such as aluminum oxide, titanium oxide; zirconium dioxide(zirconia); silicon nitride; silicon carbide; etc. other porousmaterials suitable to contain vapor (e.g. water vapor) as would beunderstood by one having skill in the art upon reading the presentdisclosure.

The reservoir may release the vapor at known rates at particular vacuumpressures, according to another approach. In yet another approach, thepressure of the vapor may be between 10⁻⁵ and 10⁻⁷ Torr. In a preferredembodiment, the pressure of the vapor may be less than 10⁻⁷ Torr,depending on the plasma energy.

In a further embodiment, the at least one write pole of the magnetichead may comprise an alloy comprising a first concentration of iron.Additionally, the at least one reader shield of the magnetic head maycomprise an alloy comprising a second concentration of iron differentthan the first concentration of iron in the at least one write pole, inone approach. For example, the at least one reader shield may comprisegreater than 30 at % iron and the at least one write pole may compriseless than 30 at % iron, in another approach. In a preferred approach,the at least one write pole may comprise 45 at % nickel and 55 at %iron, and the at least one reader shield may comprise 80 at % nickel and20 at % iron. In another exemplary approach, the at least one write polemay comprise Al—Fe—Si (Sendust), where the iron is approximately 81 at%.

According to one embodiment, the etch rate of the at least one writepole may be diminished by at least 2-3 times. According to anotherembodiment, the etch rate of the at least one write pole may bediminished by at least 6 times, 7 times, 8 times, etc. For instance, ina preferred approach where the at least one write pole may comprise 45at % nickel and 55 at % iron, and the at least one reader shield maycomprise 80 at % nickel and 20 at % iron, the at least one write polemay be etched at a rate of about 9 times slower than that of the atleast one reader shield.

Referring now to FIG. 4, a schematic diagram of a plasma sputteringapparatus 400 is shown in accordance with one embodiment. As an option,the present apparatus 400 may be implemented in conjunction withfeatures from any other embodiment listed herein, such as thosedescribed with reference to the other FIGS. Of course, however, suchapparatus 400 and others presented herein may be used in variousapplications and/or in permutations, which may or may not bespecifically described in the illustrative embodiments listed herein.Further, the apparatus 400 presented herein may be used in any desiredenvironment.

As shown if FIG. 4 according to one approach, the plasma sputteringapparatus 400 may include a chamber 402. The plasma sputtering apparatus400 may also include a reservoir 404 in the chamber 402 for releasingvapor at an established rate. In one approach, the vapor may be releasedat particular vacuum pressures. For example, in one embodiment, thevapor may be released until the pressure of the vapor is less than 10⁻⁷Torr.

The plasma sputtering apparatus 400 may additionally include a mount 406for a substrate 408. In one embodiment, the substrate 408 may include afirst material. According to another embodiment, the first material ofthe substrate may be an alloy comprising a first concentration of iron.In yet another embodiment, the substrate 408 may also include a secondmaterial, wherein the second material of the substrate may be an alloycomprising a second concentration of iron different than the firstmaterial's concentration of iron. For example, the first material maycomprise greater than 30 at % iron and the second material may compriseless than 30 at % iron, in one approach.

In a further embodiment, the presence of the vapor may diminish an etchrate of the first material of the substrate 408. Additionally, thepresence of the vapor may have a negligible effect on an etch rate ofthe second material, in one approach. For example, the etch rate of thefirst material may be at least 2 times, at least 5 times, 6 times, 7times, 8 times, etc. slower than the etch rate of the second material,in another approach. In a preferred approach, where the first materialof the substrate 408 may comprise 45 at % nickel and 55 at % iron, andthe second material of the substrate 408 may comprise 80 at % nickel and20 at % iron, the first material may be etched at a rate of about 9times slower than that of the second material.

Furthermore, the substrate 408 may include a magnetic head, such as themagnetic head illustrated in FIG. 2B according to one embodiment.According to one approach, the at least one shield of the magnetic headmay be formed of the second material, where at least one write pole ofthe magnetic head may formed of the first material.

With continued reference to FIG. 4, the plasma sputter may include aplasma source 410 of any known type. In one embodiment, the plasma mayinclude ionized argon. In another embodiment, the plasma may be excitedusing a radio frequency (RF), direct current (DC), microwave (MW), etc.energy source.

FIGS. 5A-5C and 6A-6C demonstrate different etch rates for differentmaterials. In FIG. 5A, a layer 502 of an iron alloy having greater than30 at % iron is shown with a mask 504 covering a portion thereof. FIG.5B illustrates the result of etching of the layer 502 in the absence ofwater vapor. FIG. 5C illustrates the result of etching the layer 502 inthe presence of water vapor having a pressure above 10⁻⁷ Torr underotherwise identical conditions as those used in FIG. 5B. In FIG. 6A, alayer 602 of an iron alloy having less than 30 at % iron is shown with amask 604 covering a portion thereof. FIG. 6B illustrates the result ofetching of the layer 602 in the absence of water vapor under identicalconditions as used in FIG. 5B. FIG. 6C illustrates the result of etchingthe layer 602 in the presence of water vapor having a pressure above10⁻⁷ Torr under identical conditions as those used in FIG. 5C. Note thatthe recession was retarded in FIG. 5C by the water vapor, but wasminimally retarded in FIG. 6C.

It will be clear that the various features of the foregoing systemsand/or methodologies may be combined in any way, creating a plurality ofcombinations from the descriptions presented above.

While various embodiments have been described above, it should beunderstood that they have been presented by way of example only, and notlimitation. Thus, the breadth and scope of an embodiment of the presentinvention should not be limited by any of the above-described exemplaryembodiments, but should be defined only in accordance with the followingclaims and their equivalents.

What is claimed is:
 1. A plasma sputtering apparatus, comprising: achamber; a reservoir in fluidic communication with the chamber; a vaporsource in the reservoir, the reservoir being physically configured torelease vapor from the vapor source at a predetermined rate, the vaporsource being for producing the vapor for diminishing an etch rate of afirst magnetic material, the vapor having a smaller effect on an etchrate of a second magnetic material that is different than the firstmagnetic material; a mount for a substrate; and a plasma source forgenerating an ionized noble gas, wherein the reservoir comprises, inaddition to the vapor source, an oxygenated material configured torelease oxygen during plasma sputtering, wherein the oxygenated materialis in the form of a porous structure, the vapor source being positionedin pores of the porous structure.
 2. The apparatus of claim 1, whereinthe substrate includes a magnetic head, wherein at least one shield ofthe magnetic head is formed of the second magnetic material, wherein atleast one write pole of the magnetic head is formed of the firstmagnetic material.
 3. The apparatus of claim 1, wherein the vapor iswater vapor.
 4. The apparatus of claim 1, wherein the reservoir isconfigured to release the vapor during a pump-down procedure forcreating a vacuum in the chamber.
 5. The apparatus of claim 1,comprising the substrate having the first and second magnetic materials,wherein the vapor released by the reservoir is physically characterizedas effective to diminish the etch rate of the first magnetic materialthat is an alloy comprising a first concentration of iron, wherein thevapor is physically characterized as having a smaller effect on the etchrate of the second magnetic material that is an alloy comprising asecond concentration of iron that is different than the firstconcentration of iron.
 6. The apparatus of claim 5, wherein the firstmagnetic material comprises greater than 30% iron, wherein the secondmagnetic material comprises less than 30% iron.
 7. The apparatus ofclaim 1, wherein the vapor from the vapor source reduces the etch rateof the first magnetic material by at least 2 times relative to an etchrate thereof in an absence of the vapor.
 8. A plasma sputteringapparatus, comprising: a chamber; a reservoir in fluidic communicationwith the chamber, the reservoir being configured to release a vapor atan established rate, wherein the reservoir comprises a porous materialselected from the group consisting of: a metal oxide, silicon nitride,and combinations thereof; a mount for a substrate; and a plasma sourcefor generating an ionized noble gas, wherein the porous material haspores for receiving a vapor source therein, wherein the porous materialcomprises an oxygenated material configured to release oxygen duringplasma sputtering.
 9. The apparatus of claim 8, comprising the vapor inthe reservoir.
 10. The apparatus of claim 8, wherein the porous materialis positioned to hold the substrate during plasma sputtering.
 11. Theapparatus of claim 8, comprising a vapor source in pores of the porousmaterial.
 12. The apparatus of claim 8, wherein the vapor is watervapor.
 13. The apparatus of claim 8, wherein the reservoir is configuredto release the vapor during a pump-down procedure for creating a vacuumin the chamber.
 14. The apparatus of claim 9, wherein the vapor storedin the reservoir is for diminishing an etch rate of a first magneticmaterial, the vapor having a smaller effect on an etch rate of a secondmagnetic material, wherein the first magnetic material is an alloycomprising a first concentration of iron, wherein the second magneticmaterial is an alloy comprising a second concentration of iron that isdifferent than the first concentration of iron.
 15. The apparatus ofclaim 9, wherein the vapor stored in the reservoir is for diminishing anetch rate of a first magnetic material, the vapor having a smallereffect on an etch rate of a second magnetic material, wherein the firstmagnetic material comprises greater than 30% iron, wherein the secondmagnetic material comprises less than 30% iron.
 16. The apparatus ofclaim 9, wherein the vapor stored in the reservoir is for diminishing anetch rate of a first magnetic material, the vapor having a smallereffect on an etch rate of a second magnetic material, wherein the vaporis effective to reduce the etch rate of the first magnetic material byat least 2 times relative to an etch rate thereof in an absence of thevapor.